Coordinate switch



Oct. 24, 1961 R. NITSCH 3,005,877

COORDINATE SWITCH Filed April 2, 1958 6 Sheets-Sheet 1 R. NITSCHCOORDINATE SWITCH Oct. 24, 1961 6 Sheets-Sheet 2 Filed April 2, 1958 v.m a

PP 1 A I! Oct. 24, 1961 R. NITSCH 3,005,877

' COORDINATE SWITCH Filed April 2, 1958 e Sheets-Sheet s FBJ M aizfyOct. 24, 1961 R. NITSCH COORDINATE SWITCH 6 Sheets-Sheet 4 Filed April2, 195a Oct. 24, 1961 R. NITSCH 3,005,877

COORDINATE SWITCH Filed April 2, 1958 6 Sheets-Sheet 5 I a i I I l Oct.24, 1961 R. NlTSCH 3,005,877

COORDINATE SWITCH Filed April 2, 1958 6 Sheets-Sheet 6 dify UnitedStates Patent 3,005,877 COORDINATE SWITCH Rudolf Nitsch, Munich,Germany, assignor to Siemens and Halske Aktiengesellschaft Beriin andMunich, a

corporation oi? Germany Filed Apr. 2,1958, Scr. No. 726,006 Claimspriority, application Germany Apr. 5, 1957 15 Claims. (Cl. 179-2754)This invention is concerned with improvements relating to coordinateswitches of the type described in copending application Serial No.573,039, filed March 21, 1956, and Patent No. 2,983,792, dated May 9,1961, both owned by the assignee named in the present case, for use insignalling systems, especially telephone systems, such switchescomprising mutually crossing line and row actuating coils as well asauxiliary holdingcoils which respectively embrace the entirecorresponding line or row. The terms line and row are intended todesignate difierent coordinate directions. At the crossing points ofthese coils are provided contact sets constructed of contact springsenclosed within protective tubing. The corresponding switch is providedwith a magnetic shunt containing an iron path, serving to preventactuation of the contacts responsive to energization of only a line coilor only a row coil. The iron path contained in the shunt consists ofrectangularly abutting metallic strips or sheets disposed about thecontact sets.

Theresult of the above indicated disposition of parts is a structurewherein pairs of metallic sheets or strips cooperate with the ends ofthe contact springs extending from the respective protective tubings,such strips being, for example, common to an entire row of thecorresponding switch, and wherein the respective holding coils alwaysembrace an entire line of the switch.

The various objects and features of the invention will be brought out inthe course of the explanations which will be rendered below withreference to the accompanying drawings. In the drawings FIG. 1 shows theinitially indicated parts of a switch and its tube-protected contactsets; other switch parts have been omitted to simplify representationand description; 7

FIG. 2 illustrates a switch with four crossing points each provided witha tube-protected contact set having four contacts;

FIGS. 3a and 3b represent an individual contact included in thestructure according to FIG. 2;

FIG. 4 indicates in sectional view, taken at the contact spring airgaps, a contact structure according to FIGS. 3a and 3b;

FIG. 5 explains the non-uniform influence of the magnetic shunt on thesprings of a contact;

FIGS. 6 and 7 show contact sets comprising magnetizable insert membersto equalize or compensate the nonuniform eifect of the magnetic shunt;

FIG. 8 illustrates a contact set comprising compensating or equalizinginserts resulting from a combination of the features incorporated inFIGS. 6 and 7;

FIG. 9 explains the operation of a magnetizable insert;

FIG. 10 shows the use of permanently magnetized insert members in aswitch; and

FIGS. 11a and 11b represent a contact set comprising four tube-protectedcontacts equipped with a magnetic shunt and with permanently magnetizedinsert members according to the invention.

Referring now to FIG. 1, showing the switch parts according to theinitially indicated structure, when the holding coil H1 is energized, itwill impress a magnetic flux on the tube-protected contacts embracedthereby, which will hold openatively actuated contacts in their actuatedpositions. It will be seen from FIG. 1 that a magnetic circuit willthereby result involving the contact sets I and II, the outwardlyextending ends of the contact springs of which are magnetically coupledby means of the metallic strips of sheets Nl-NZ and N9-N10. The arrowspointing in FIG. 1 to the right indicating the direction of thecorresponding fluxes. On the contact set II is thereby impressed anundesired flux extending in a direction opposite to the direction of thedesired holding flux, as indicated by the arrows pointing to the left.In case the holding coil (not shown) disposed underneath the coil H1should also be energized, the fluxes produced by the two holding coilswould be superposed, causing weakening of the holding flux resultingwith respect to one contact set. A complete compensation does not takeplace since the main part of the flux produced by one holding coil isclosed by way of the iron path which embraces the contact sets in themanner of a cage. The consequence of the superimposing of the fluxesresponsive to energization of two holding coils is, that strongerholding energization must be applied.

The invention, showing a way to void these difliculties, is therebycharacterized that those of the pairs of metallic strips or sheets whichefiect the magnetic coupling for the ends of the contact springsextending from the contact sets to the outside, at the side where theholding coil is disposed, are so arranged, that they do not produce amagnetic coupling between contact springs controlled by differentholding coils.

The pairs of metallic strips forming the magnetic coupling for the endsof the contact springs which extend from the contact sets at the otherside are advantageously likewise arranged so as to avoid magneticcoupling between contact springs controlled by other holding coils.

The result is a structure which provides for each contact set two outermetallic strips and two centrally disposed metallic strips, one outerpair of strips embracing one energizing or actuating coil, the otherouter pair embracing the holding coil, and the centrally disposed pairof strips embracing the other actuating coil, whereby the metallicstrips which embrace the actuating coils are interlocked by means ofslots, thus providing the magnetic coupling for the movable parts of thecontact springs at the air gap formed thereby.

FIG. 2 illustrates a structure which meets the above statedrequirements. The figure shows four crossing points of a switch, eachcrossing point being provided with a tube-protected contact setcomprising four contacts. Among the actuating coils of the switch arethe line coil A, the row coil C and the holding coil H1. At the crossingpoint between the line coil A and the row coil C is disposed a contactset comprising four tube-protected contacts 11, 12, 13, 14. The holdingcoil H1 is embraced by a pair of metallic strips N7 and N8 which alsoform the magnetic coupling for the ends of the contact springs extendingat the corresponding side from the protective tubings to the outsidethereof. A pair of metallic strips N3 and N4 embraces the line actuatingcoil A in similar manner. Between the two pairs of strips N7, N8 and N3,N4 is disposed another pair of metallic strips N5, N6 which embraces therow actuating coil C. The pairs of metallic strips N3, N4 and N5, N6 areinterlocked and form the magnetic coupling for the movable parts of thecontact springs at the air gaps formed thereby.

A magnetic coupling affecting contacts sets which are not embraced byone and the same holding coil (as in FIG. 1), is in FIG. 2 only possibleby stray flux passing through the air. Such stray flux will decrease inaccordance with decreased magnetic impedance of the iron path affectingthe ends of the contact springs. The centrally disposed metallic stripsN5, N6 embracing the actuating coil C and the metallic strips N7, N8embracing the holding coil H1 are for this purpose angularly bent in thedirection of the contact spring sets. The bent portions abut and formthe magnetic coupling for these pairs of metallic strips. Thecorresponding angular configuration provides for a large engagingsurface, resulting in a low magnetic impedance, and also forms a shapewhich is favorable for the insertion of the coils. The entire structureis in the assembling of the parts pretensioned so that the pairs ofmetallic strips are for good magnetic contacting in mutually firmengagement.

FIGS. 3a and 312 show two views, with some parts in section, of thecontact set and associated parts, included in the switch illustrated inFIG. 2, which is provided with the iron path of the magnetic shunt madein accordance with the invention and comprises the contact springs 11 to14; FIG. 3a showing the contact set and associated parts as seen in FIG.2 from the side and FIG. 3b showing the contact set and associated partsturned by 90 and looking down. For the sake of clarity, the parts of theiron path disposed in the direction of viewing FIGS. 3a and 3brespectively in front and in back of the contact set, have been omitted,thus showing in sections only the parts of the iron path positionedlaterally of the contact set. The tube-protected contacts K are at theirends embraced by the pairs of metallic strips N3, N4 and N7, N8,respectively, such strips also respectively enclosing the line coil Aand the holding coil H1. The portions of the metallic strips N3, N4extending from the actuating coil A in straight manner beyond theprotective tubes K to the left, thus forming openings at the side of theswitch Where the line actuating coils are located through which thetube-protected contacts can be inserted. The metallic strips N7, N8 are,however, angularly bent in close proximity to the ends of the contactsprings extending from the protective tubes. In case the spacing of thestraight metallic strips N3, N4 from the ends of the contact springsextending from the protective tubes to the left, should result inundesirably high magnetic transition impedance with respect to such endsof the contact springs, magnetizable inserts may be used so as toprovide the required magnetic connection. Disposed between the pairs ofmetallic strips N3, N4 and N7, N8 is the pair of metallic strips N5, N6which interlock with the strips N3, N4, to provide the magnetic couplingfor the contact springs at the air gap thereof, such strips N5, N6 beingangularly bent to form portions lying close to the contacts. The pair ofstrips N5, N6 embraces the row actuating coil C. The right hand endwalls of the strips N5, N6 abut similar left hand end walls of thestrips N7, N8, thus interconnecting the corresponding stripsmagnetically.

FIG. 4 shows a section of the contact set of FIGS. 3a, 3b, taken along aline which intersects the air gap formed by the contact springs. Thefour tube-protected contacts K are enclosed Within the four metallicstrips N3, N4, N5 and N6, as in a cage. It will be seen that the contactsprings Fa lying close to the metallic strips N3, N4 have a bettermagnetic connection to these metallic strips than the contact spring Filying on the inside. The effect of the magnetic shunt with respect tothe individual contact springs of the contact set is, therefore,non-uniform.

FIG. 5 explains the non-uniform influence of the magnetic shunt,illustrating only one tube-protected contact K engaged by a portion ofthe metallic strip N3. The non-uniform magnetic effect of the shunt isdue to the different spacing of the contact springs F1 and Fa from thestrip N3, spring Fa lying closer thereto than spring Fi. The effect ofthe magnetic shunt is, accordingly, undesirably weakened so far as thecontact spring Pi is concerned.

This drawback may be avoided by the provision of magnetizable insertsplaced between the individual tube-pro tected contacts to affect thecontacts in the region of their air gaps.

FIGS. 6 and 7 show examples for the use of such incerts, the figuresagain showing contact sets each comprising four tube-protected contacts.In the case of FIG. 6, there is provided a vertically extending insertZs, and in the case of FIG. 7, there is provided a horizontallyextending insert Zp. These inserts are magnetically connected with thepairs of metallic strips which embrace the respective contact sets,causing deflection of the stray fluxes preferentially from the innermostcontact springs F1. The inserts are advantageously held in suitableslots formed in the pairs of metallic strips so as to obtain goodmagnetic connections.

In the structure according to FIG. 7, the wide surfaces of the contactsprings are always opposite a metallic strip or an insert, respectively,thus providing an effect of the magnetic shunt on both contact springsof such contact which is more uniform than in FIG. 6.

FIG. 8 shows a combination of the features of FIGS. 6 and 7. There areprovided inserts Zp and Zs in crossing relationship, thus forming foreach contact an individual cage which encloses the contact symmetricallyand thereby elfecting the most uniform action of the magnetic shunt onthe individual contact springs.

The inserts may also serve for producing a particular effect, namely, toreduce the expenditure required for the energization :of the holdingcoils. The inserts are for this purpose permanently magnetized parallelto the axis of the tube-protected contacts so as to obtain closure ofthe resulting stray flux across the contact air gap. Such a permanentlymagnetized insert may be disposed in parallel with or perpendicular tothe contact springs.

The cost of hard magnetic material represents an important item and itis therefore advantageous to place the permanently magnetized insert sothat it can perform in the best possible manner, thereby reducing theuse of the expensive material to a minimum. This will be the case whenthe permanently magnetized insert is disposed in parallel with thecontact springs, as shown in FIG. 7. For example, the insert Zp, in FIG.8, may be made of magnetically hard material and the insert Zs may bemade of magnetically soft material.

The operation of the permanently magnetized insert may be explained withreference to FIG. 9, showing a tube-protected contact K comprisingcontact springs Pa and Ft. The metallic strip N3 and the permanentlymagnetized insert Zp are disposed opposite one another in the region ofthe air gap between the contact springs Fa, Fi. The insert produces astray flux flowing in the direction of the arrows, such flux closingacross the air gap and thus exerting upon the contact springs anattractive force; such force is, however, by itself insuflicient to holdthe contact in actuated position and is, of course, wholly inadequate toeffect operative actuation of the contact. Flux produced by the insertZp flowing across the contact air gap in the same direction as the fluxproduced by the holding coil will support the latter, and theexpenditure required for the energization of the holding coil canaccordingly be reduced; if the fluxes flow in opposite directions, itwill be necessary to provide for stuonger energization of the holdingcoil. Either effect may gain importance with respect to variousoperating requirements.

The material to be used for the permanently magnetized inserts should beadapted for rolling and machining including cutting, so as to facilitatethe shaping of the inserts.

FIG. 10 shows a structure employing permanently magnetized insertsaccording to FIG. 9. The illustrated switch has four crossing pointseach with a contact set comprising four tube-protected contacts.Accordingly, there are two line control coils A and B, two row controlcoils C and D, and two holding coils H1 and H2. The permanentlymagnetized inserts, indicated at Zpl and Z 22 are respectively commoneach to a row. The direction of magnetization of the insert Zpl isindicated by the arrow.

FIGS. 11a and 11b are two part sectional views of a contact setcomprising four tube-protected contacts and provided with the magneticshunt and the inserts according to the invention. The structure isgenerally similar to that shown in FIGS. 3a, 3b and identical parts are,therefore, identically referenced. FIG. 11b shows the contact setrotated with reference to FIG. 11a by 90. The parts of the iron pathlying in viewing direction respectively in front and in back of thecontact set have again been omitted, only the parts being shown insection which lie laterally of the contact set. Within the region of thecontact air gap are disposed the inserts Zp and Zs. The inserts and alsothe metallic strips serve advantageously a whole line and a whole row ofthe switch. Such inserts also appearin FIGS. 2 and 10.

In FIG. 2, the corresponding inserts are marked Zp and Zr. They extendthnough the contact sets and the pairs of metallic strips N5, N6 and N3,N4- within the region where the metallic strips engage thetube-protected contacts. The inserts are held in slots formed in thesemetallic strips.

Changes may be made within the scope and spirit of the appended claims.

I claim:

1. A coordinate switch for use in a signalling system, said switchhaving a plurality of similarly disposed contact sets transverselyaligned in two coordinate directions, each contact set comprising aplurality of tube-protected contacts with the ends of the correspondingcontact springs extending outwardly, and having a first actuating coilembracing a plurality of contact sets aligned in one coordinatedirection and a second actuating coil disposed in crossing relationshipwith respect to said first coil and embracing a plurality of contactsets aligned in the other coordinate direction, and including a holdingcoil common to the contact sets embraced by one of said actuating coils,and further having a magnetic shunt containing an iron path formed byrectangularly abutting metallic strips which enclose the contact setdisposed at the crossing point of said first and said second actuatingcoils, said iron path being operative to effect magnetic coupling-withrespect to said outwardly extending ends of the contact springs of thecorresponding contact set, the metallic strips forming said iron path inthe vicinity of said holding coil extending with respect to thecorrespondingly placed outwardly extending ends of said contact springsso as to efiect responsive to energization of said holding coil solelymagnetic coupling of said correspondingly placed ends of said contactsprings and thus avoiding magnetically aflecting neighboring contactsprings operatively associated with other holding coils.

2. A coordinate switch according to claim 1, wherein said iron pathenclosing said contact set comprises two pairs of outer metallic stripsrespectively embracing said contact set at the opposite ends thereof, afurther pair of metallic strips embracing such contact set within aregion lying intermediate said first named two pairs of outer metallicstrips, one of said pairs of outer metallic strips embracing one of saidactuating coils, the other pair of said outer metallic strips embracingsaid holding coil, said further intermediate pair of metallic stripsembracing the other one of said actuating coils, and means formechanically interlocking the two pairs of strips which respectivelyembrace said actuating coils to provide magnetic connection therebetweenwhich is upon energization of said actuating coils effective to producea flux flowing across the air gap formed by the contact springs of saidtube-protected contacts.

3. A coordinate switch according to claim 2, wherein the ends of themetallic strips of said intermediate pair and the ends of the metallicstrips of the outer pair which embrace said holding coil arerespectively angularly shaped, such angularly shaped ends of said stripsabutting to connect the respective pairs of strips magnetically.

4. A coordinate switch according to claim 1, comprising magneticallyconductive insert means disposed between certain pairs of adjacent tubesof said contact set with the contacts of one tube of a pair disposed atone side of said last mentioned means and those of the other tube ofsuch pair disposed at the other side of said last mentioned means, themagnetic flux produced by said insert means atfecting the region of saidcontacts including the air gap formed by the corresponding contactsprings, said inserts being magnetically interconnected with themetallic strips embracing the corresponding contact set along suchregions.

5. A coordinate switch according to claim 2, comprising magneticallyconductive insert means disposed between certain pairs of adjacent tubesof said contact set with the contacts of one tube of a pair disposed atone side of said last mentioned means and those of the other tube ofsuch pair disposed at the other side of said last mentioned means, themagnetic flux produced by said insert means afiecting the region of saidcontacts including the air gap formed by the corresponding contactsprings, said inserts being magnetically interconnected with themetallic strips embracing the corresponding contact set along suchregions.

6. A coordinate switch according to claim 3, comprising magneticallyconductive insert means disposed between certain pairs of adjacent tubesof said contact set with the contacts of one tube of a pair disposed atone side of said last mentioned means and those of the other tube ofsuch pair disposed at the other side of said last mentioned means, themagnetic flux produced by said insert means affecting the region of saidcontacts including the air gap formed by the corresponding contactsprings, said inserts being magnetically interconnected with themetallic strips embracing the corresponding contact set along suchregions.

7. A coordinate switch according to claim 1, comprising permanentlymagnetizable insert means disposed between certain pairs of adjacenttubes of said contact set with the contacts of one tube of a pairdisposed at one side of said last mentioned means and those of the othertube of such pair disposed at the other side of said last mentionedmeans, said insert means being magnetized in a direction extending inparallel to the axes of said tubeprotected contacts, the stray fluxproduced by said insert means flowing across the air gap formed by thecorresponding contact spring.

8. A coordinate switch according to claim 2, comprising permanentlymagnetizable insert means disposed between certain pairs of adjacenttubes of said contact set with the contacts of one tube of a pairdisposed at one side of said last mentioned means and those of the othertube of such pair disposed at the other side of said last mentionedmeans, said insert means being magnetized in a direction extending inparallel to the axes of said tube protected contacts, the stray fluxproduced by said insert means flowing across the air gap formed by thecorresponding contact spring.

9. A coordinate switch according to claim 3, comprising permanentlymagnetizable insert means disposed between certain pairs of adjacenttubes of said contact set with the contacts of one tube of a pairdisposed at one side of said last mentioned means and those of the othertube of such pair disposed at the other side of said last mentionedmeans, said insert means being magnetized in a direction extending inparallel to the axes of said tubeprotected contacts, the stray fluxproduced by said insert means flowing across the air gap formed by thecorresponding contact spring.

10. A coordinate switch according to claim 4, wherein said insert meansis common to a plurality of contact sets disposed in a predeterminedcoordinate direction.

11. A coordinate switch according to claim 5, wherein said insert meansin common to a plurality of contact sets disposed in a predeterminedcoordinate direction.

12. A coordinate switch according to claim 6, wherein said insert meansis common to a plurality of contact sets disposed in a predeterminedcoordinate direction.

13. A coordinate switch according to claim 7, wherein said insert meansis common to a plurality of contact sets disposed in a predeterminedcoordinate direction.

14. A coordinate switch according to claim 8, wherein said insert meansis common to a plurality of contact sets disposed in a predeterminedcoordinate direction.

15. A coordinate switch according to claim 9, wherein disposed in apredetermined coordinate direction.

2,187,115 2,245,391 2,289,830 2,324,623 2,332,338 2,397,123 said insertmeans is common to a plurality of contact sets 10 2,836,676

References Cited in the file of this patent UNITED STATES PATENTSEllwood Jan. 16, Dickten June 10, Ellwood July 14, Hickman July 20, 1943Peek Oct. 19, Brown Mar. 26, Wirth May 27,

